The 4” Model G-4000P Electric Release Preaction System Riser Assembly can be used as a Single Interlock Preaction System with Electric Release, or as a Double Interlock Preaction System with Electric/Pneu-Lectric Release. These preaction systems are commonly used where it is important to control accidental water discharge due to inadvertent damage to the sprinkler piping. The small profile, lightweight, pilot operated Viking G-4000P Valve comes complete as shown on the Datasheet.